According to the requirement of servo control system for valve servo circuit. The author present a new design of circuit to solve the problem which is widely exists in the servo circuit that the structure of circuit is comp licated and the realtime performance is low. The new design is based on the AD698 as the core of Linear Variable Differential Transformer (LVDT) signal process, with ST’s ARM chip STM32F051 and Lattice’s FPGA chip XP2 PQFP208. The function and hardware structure of the controller and software flow has been given. Experimental results show that the design can improve the circuit performance effectively. It has the characteristics of portability, simple construction, high integrity and more realtime. The system can meet the requirement of servo control system for power of driving,the accuracy of measurement ,and stability of it.